Figured out how to make a 2 stage Fenix twisty -- It Works

wwglen

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Looking at the photos in:

https://www.candlepowerforums.com/posts/1089436&postcount=18

and trying somethings out I think I have figured out how to make the switch into a two stage twisty where the cliclie switch determins the level.

I also have a more involved method that would give it a two stage clicky determined by the twisting of the tail cap.

I haven't done this but I will do method 1 as soon as I get a surface mount 10-15 ohm resistor I will.

Method 1: (Easy)
Look at the second picture in the post referenced above.
Take a 10 ohm resistor (preferably surface mount) and solder it across the two conductive pads on the circuit board.

Do it so the surface mount resistor is under the o-ring that keeps the spring from touching the threaded mounting ring.

This will allow a small current to flow through the flashlight when the clicky is OFF and when the clicky is on the light will be at full brightness.

Use the switch as a twisty as some people here already do but leave the clicky in the position you want the light.


Method 2:

Drill a hole in the threaded mounting ring.

Place a SMALL isolated spring (or plunger) in the hole so it sticks out a little above the mounting ring.

Run a wire from the spring to a surface mounted resistor that is also connected to the inner conducting ring on the board.

The spring (or plunger) will make contact to the battery tube BEFORE the surface of the mounting ring.

This will allow a small current flow (LOW) when ON and the switch assembly is slightly untwisted.

With the switch assembly all the way twisted in the light will be full brightness.

Brightness levels using a rechargable battery holding a resistor across the battery and body of the flashlight.

Resistance values are approximate.

10 Ohm -- Just right for me a little less than an arc AAA (old style) but MORE throw.

20 Ohm -- Good for close up in a pretty dark room. Still a lot of throw and you could read and move around after you eyes got used to it.

50 Ohms -- A slight glow which would make a good "find me" mode. You can read with it if you have GOOD eyes and hold the light close. You can bairly see enough to move around a dark room with adjusted eyes but I wouldn't count on it.

I didn't measure current flows but the 50 Ohm would probably be in the < 1 mA range based on the brightness compaired to a MJLED running at 4-5 mA.


wwglen
 
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phatalbert

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Re: Figured out how to make a 2 stage Fenix twisty

Whoa! I'm totally excited about method 2. Someone needs to do that and post step by step pics. It would also be awesome if it could be done with universally available parts (radio shack, Lowes, etc.) :popcorn:

What would be the approximate runtime on the 10 ohm? 20 ohm?
 
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LightObsession

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Re: Figured out how to make a 2 stage Fenix twisty

Interesting, I also look forward to someone trying this.
 

chrisse242

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Re: Figured out how to make a 2 stage Fenix twisty

Method one sounds more appealing to me. Very easy to do. I'll have to check the resistance of some of the smd-resistors that I've lying around here, maybe I'll try it tonight.

Chrisse
 

wwglen

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Re: Figured out how to make a 2 stage Fenix twisty

Radioshack doesn't sell surface mount resistors in their store.

If anyone has one 10-20 ohm that I could use to try this mod I would appreciate it.

Thanks,

wwglen
 

wwglen

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Re: Figured out how to make a 2 stage Fenix twisty

Alos I have been thinking that depending on the thickness of the SMT and the solder connection you MIGHT need to put a THIN metal ring or washer around the outside of the circuit board so that the mounting ring will make contact evenly around the entire circuit board and not put stress on the solder joint.

wwglen
 

greenLED

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Re: Figured out how to make a 2 stage Fenix twisty

wwglen said:
Method 1: (Easy)
...
This will allow a small current to flow through the flashlight when the clicky is OFF and when the clicky is on the light will be at full brightness.

I'm confused, does this means the light is always on? Or is the sequence: lock-out (off) - slight twist (low) - complete twist (high)?
 

wwglen

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Re: Figured out how to make a 2 stage Fenix twisty

The light will work like a twisty.

The Fenix has a fairly smooth tail cap and some people like to use it as a twisty anyway. With the manufacturing tolerences it only takes about 1/8-1/4 turn on the tail cap to turn it on and off.

SO...

The switch will always be "ON" in either the LOW (switch off) or HIGH (switch on) and you can turn the light on and off by using the tailcap like a twisty.

While i REALLY like option 2 above I think option 1 is do-able by myself or anybody that has a soldering iron/surface mount resistor and MAYBE a thin contact ring (depending on how smooth you solder on the SMT resistor.

Since I do not currently have a SMT resistor I might just get the smallest regular 10 ohm resistor from radio shack and Kludge it together before I go camping NEXT weekend with the boyscouts. It wount be pretty and it won't be my long term solution but I am sure I can make it work.

Sequence:

Lockout (off) --> Twist on --> Click switch when on to switch hi/low
wwglen.
 
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BackBlast

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Re: Figured out how to make a 2 stage Fenix twisty

Very nice, I like this easy mod.. My only question is what kind of runtime would a low mode produce? Are you going to be losing a lot of power to the resistor?
 

phatalbert

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Re: Figured out how to make a 2 stage Fenix twisty

Can somebody tell (show) me the difference between a regular resistor and a surface mount? :shrug:
 

kennyj

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Re: Figured out how to make a 2 stage Fenix twisty

Here's my suggestion for method 3: Remove a segment from the mounting ring with a Dremel, and fill a part of this gap by soldering one end of an SMD to one of the cut ends of the mounting ring. Make sure it sits in such a way that the free end won't contact the circuit board or any part of the the light body when the ring is replaced. Then, get some foam rubber, and cut it in such a way as to fill the gap between the SMD and the other cut end of the ring. It should be thick enough that it sits flush with the mounting ring's faces on both sides (doesn't have to be perfect though.) Solder a small wire to the free end of the SMD (you can do this first if you have to) and to this small wire, anything that can work as a contact (like a lump of solder, but preferrably a thicker bit of wire or something.) This contact goes on top of the foam rubber and is attached by epoxy. No part of the contact, its connecting wire, or the "free" end of the SMD should touch the outer place of the circuit board or the light body. What you should have here is a module that fully contains itself within the dimensions of the mounting ring.

What should happen is this: The tailcap starts off unscrewed (or in lockout mode, in marketing speak.) You start tightening it, and you hit the contact that sits on the foam rubber - which holds it just above the mounting ring. You screw down further, and the foam compresses. The only metal part that flexes... is the flexible wire. Once the contact is pressed into the foam a bit, the mounting ring hits the light body. At no point, however, will the light turn on while the switch is turned off. If the switch is left on all the time, however, you can simply untwist until no electrical connection is possible (lockout mode.) As a result, you either control the power with the tailcap switch and adjust output by twisting, or you do it all by twisting and ignore the switch (assuming you leave it on.) As an added bonus, there isn't a small, fragile spring to worry about pinching or torquing, just a bit of foam rubber that can be squeezed a million times, and a flexible wire that can bend a teeny bit pretty much forever.
 

phatalbert

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Re: Figured out how to make a 2 stage Fenix twisty

This is exciting. Once these go from theory to photographed application, I'll bust out the dremel. :popcorn:
 

wwglen

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Re: Figured out how to make a 2 stage Fenix twisty

You WILL lose some power over the resistor but the runtime will be GREATLY increased.

On LOW with a 10 ohm resistor I would expect at LEAST 3x the run time and proably a lot longer.

wwglen
 

eoed

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Re: Figured out how to make a 2 stage Fenix twisty

Hi, here is my friend's testing photos.
30 SMD resitors cost him around $1 USD. :rock:

with 5.1 ohm SMD resistor LOW
low.jpg


HIGH
high.jpg
 

wwglen

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Re: Figured out how to make a 2 stage Fenix twisty

Where did he get the resistors?

Thanks,

wwglen
 

eoed

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Re: Figured out how to make a 2 stage Fenix twisty

wwglen,
We're from Taiwan :p
He bought the resitor in "electronic street" where stores all sell electronic devices in that street.
 

wwglen

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Re: Figured out how to make a 2 stage Fenix twisty

I saw that after I posted.

I guess it is a little far to walk.

wwglen
 

Robban

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Re: Figured out how to make a 2 stage Fenix twisty

phatalbert said:
Can somebody tell (show) me the difference between a regular resistor and a surface mount? :shrug:
Here's a couple of random pictures I found on google image search.

"Standard" resistor, the kind people usually think about when talking about resistors:
http://twinoak.altelco.net/~jacil/clay/motorcycle/bulb4b.jpg

Surface mount. That weee thing on his finger
http://www.al7fs.us/P5210013 SMD large resistor 65pc.JPG
 
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